PDA

View Full Version : Soft corners and vignetting


SadChi
9-Sep-2008, 12:44
Hello,

If there are any other than Petzval lenses that have soft corners and severe vignetting?

Thanks,
Ash
9-Sep-2008, 13:10
Not that your request makes much sense, but if that's what you want, then you need to go for a petzval made for a smaller format than you want to shoot.

For example, a 5x7 camera with a petzval-type lens designed for 5x4. That way the coverage is smaller than the format, causing vignetting.
SadChi
9-Sep-2008, 13:16
I saw several image where Petzval lens didn't cover the film it was interesting. So i want to try such effect, but small petzvals (for example from Jim Galli) disappear really fast.
BarryS
9-Sep-2008, 13:25
A lot of older lenses used on a format larger than intended will produce vignetting and soft corners. I've been trying some rapid rectilinear lenses and while they don't produce the same effects as a petzval--they can produce some nice soft corners and vignetting if you find one made for a format smaller than your camera. But there are a lot of possibilities--projector lenses, magnifying lenses, lenses off junker cameras. It just takes a little experimenting. Another option is just contacting Jim and telling him what you're looking for.
IanG
9-Sep-2008, 13:52
Yes an under-sized Tessar, like a 105mm on a 5x4. B etter still a 3 element Trinar or similar.

Ian
seven
9-Sep-2008, 14:15
you need a petzval for the swirl effect.
just for vignetting use a lens with smaller coverage than the format you're shooting.
Brian Ellis
10-Sep-2008, 08:18
you need a petzval for the swirl effect.
just for vignetting use a lens with smaller coverage than the format you're shooting.

Or get a step down ring and a UV filter and put it on a lens you already own. It's easy to get vignetting, I've ruined more than one otherwise good photograph because of vignetting.
Toyon
10-Sep-2008, 08:27
Rapid rectilinear lenses are soft at the edges when wide open. It is less dramatic than with petzvals. Use a lens designed for your format or slightly smaller to maximize the effect. Also, dagors, have much larger coverage than their zone of sharpness. My 120mm covers 8x10, but sharply only in the center.
Ole Tjugen
10-Sep-2008, 09:03
The old Xenar Typ D wide open is swirlier than most Petzvals, even on the format it's supposed to cover.

The swirlies seem to be a result of a very large maximum aperture more than anything else.
SadChi
10-Sep-2008, 09:06
The old Xenar Typ D wide open is swirlier than most Petzvals, even on the format it's supposed to cover.

The swirlies seem to be a result of a very large maximum aperture more than anything else.

Ole,

How to distinguish the Xenar type D from other?

Thanks.
Ole Tjugen
10-Sep-2008, 10:17
They are clearly marked with "Typ D". They will also be in odd-sized dial-set Compur or Copal shutters. Mine is a 150mm f:3.5 - and is a "reverse Tessar" unlike the triplet that is commonly described. Maybe some of the other f:3.5 reverse Tessars will be as swirly? I don't know, since I only have the one.